How to take only first line from the multiline text

c#, regex

Solution

string test = @"just take this first line
even there is 
some more
lines here";

Match m = Regex.Match(test, "^(.*)", RegexOptions.Multiline);
if (m.Success)
    Console.Write(m.Groups[0].Value);

`.` is often touted to match any character, while this isn't totally true. `.` matches any character only if you use the `RegexOptions.Singleline` option. Without this option, it matches any character except for `'\n'` (end of line).

That said, a better option is likely to be:

string test = @"just take this first line
even there is 
some more
lines here";

string firstLine = test.Split(new string[] {Environment.NewLine}, StringSplitOptions.None)[0];

And better yet, is Brian Rasmussen's version:

string firstline = test.Substring(0, test.IndexOf(Environment.NewLine));

Problem

Original source